Assessment of Microbiologically Influenced Corrosion of Metals in Biodiesel fromJatropha curcas S.Malarvizhi and R.Shyamala Avinashilingam Institute for Home science and Higher Education for Women CoimbatoreTamilnadu India. Email: s.malarvizhi@gmail.com Sankara Papavinasam CorrMagnet Consulting Inc. 6 Castlemore Street Ottawa Ontario Canada. Email:spapavin@corrmagnet.com ABSTRACT Use of biodiesel provides promising opportunities for immediately addressing our energy security issues. Being plant based biodiesels are more hygroscopic and more readily biodegraded than fossil fuels and the introduction and wide spread use of biodiesels in the existing fuel infrastructure may lead to increased problems of microbiologically influenced corrosion (MIC). Effective control and prevention of MIC requirean underlying knowledge of the microbes that survive in biodiesel and the ingredients that help in their growth. This paper discusses the corrosion of aluminium and copper inJatropha curcas biodiesel and its blends with commercial diesel under the influence of bacteria isolated from the sediments of stored jatropha biodiesel by mass loss measurements. The results indicate that both the metals show highest corrosion rate in B100.Keywords: Hygroscopic MIC Jatropha curcas biodiesel aluminium copper biodiesel blends